Tire-building drum

ABSTRACT

A tire-building drum of the collapsible type having a plurality of segments which, in the expanded condition of the drum, collectively form a tire-building surface. Radial movement of the segments between the expanded and collapsed condition of the drum is controlled by two sets of links one of which set has a through center toggle action as the segments associated therewith move into or out of expanded condition. The segments are guided in their radial movement by pistons mounted on the segments and received in cylinders which are fixed relative to the drum shaft. In the expanded condition of the drum, the links are contained within the pistons to provide a compact structure. The foregoing abstract is not to be taken as limiting the invention of this application, and in order to understand the full nature and extent of the technical disclosure of this application, reference must be made to the accompanying drawing and the following detailed description.

O United States Patent [151 3,644,162 Appleby et al. 1 Feb. 22, 1972 [54] TIRE-BUILDING DRUM [57] ABSTRACT inventors; Pllll PP Y, silvel'lake; Denver C- A tire-building drum of the collapsible type having a plurality F Akron; Robe" 888, t all of segments which, in the expanded condition of the drum, of Ohio collectively form a tire-building surface. Radial movement of t the segments between the expanded and collapsed condition [73] Asslgnee' ni fi zg The Rubber company of the drum is controlled by two sets of links one of which set has a through center toggle action as the segments associated [22] Filed: July 6, 1970 therewith move into or out of expanded condition. The segments are guided in their radial movement by pistons mounted [21] Appl' 52232 on the segments and received in cylinders which are fixed relative to the drum shaft. In the expanded condition of the drum, [52] U.S.Cl ....l56/4l5, 156/420 the links are contained within the pistons to provide a com- [51] Int. Cl. ..B29h 17/16 pact structure.

[58] Field of Search ..89/414, 415, 417, 420 The foregoing abstract is not to be taken as limiting the invem tion of this application, and in order to understand the full na- [56] Reterem Cited ture and extent of the technical disclosure of this application, N E STATES PATENTS reference must be made to the accompanying drawing and the I following detailed description. 3,485,700 12/1969 Cooper et al. ..l56/417 12 Claims, 4, Drawing Figures Primary Examiner-Benjamin A. Borchelt Assistant Examiner-Stephen C. Bentley A Attorney-F. W. Brunner and M. William Goodwin TIRE-BUILDING DRUM This invention relates to tire-building drums and more particularly to a novel and improved tire-building drum of the collapsible type.

It is the primary object of the present invention to provide a novel and improved tire-building drum of the collapsible type which will provide a relatively simple and compact structure, yet which will provide accuracy in tire building comparable to drums of more complex structure.

It is a further object of the present invention to provide a tire-building drum of the type described which is readily converted to build tires of different lengths and diameters and which can be readily and economically maintained.

Other objects will be in part obvious, and in part pointed out more in detail hereinafter.

The invention accordingly comprises the features of construction, combination of elements and arrangement of parts which will be exemplified in the construction hereafter set forth and the scope of the application of which will be indicated in the appended claims.

In the drawing:

FIG. 1 is a longitudinal cross-sectional view of a tire-building drum constructed in accordance with the present invention;

FIG. 2 is an end view as viewed at 2-2 in FIG. 1;

FIG. 3 is an end view similar to FIG. 2 but with the drum in collapsed condition; and

FIG. 4 is a fragmentary, enlarged, cross-sectional view substantially along the line 4-4 of FIG. 1.

With reference to the drawing, a drum constructed in accordance with the present invention comprises an elongated tubular shaft of circular cross section. Disposed coaxially within the shaft 10 is a lead screw 12 having two portions 14 and 16 of opposite hand. The lead screw portions 14 and 16 are joined together by coupling 18 to provide for simultaneous rotation of the lead screw portions. A pair of lead nuts 20, 22 are threaded over the lead screw portions 14 and 16, respectively, whereby rotation of the lead screw 12 in one direction will effect simultaneous but opposite movement of the lead nuts 20, 22 in directions axially of the shaft 10. The lead nuts 20, 22 have cylindrical outer surfaces which are slidingly engaged with the inner cylindrical surface of the shaft 10.

Disposed concentrically about the shaft 10 are a pair of sleevelike members 24, 26 which are supported by friction bearings as at 28 for sliding movement longitudinally of and along the outer cylindrical surface of the shaft 10. The outer surface of each of the members 24 and 26 is polygonal and is in the specific embodiment as shown in FIG. 2 substantially hexagonal to provide six flat surfaces, as at 30, disposed equiangularly about the axis of the shaft 10. Mounted on the sleeves 24, 26 in overlying relation to each of the flat faces 30, respectively, are a plurality of blocks 32 which are suitably fixed to the sleeves. A pair of pins 34 are carried by two of the blocks 32 associated with each of the sleeves 24, 26. The pins 34 extend radially of the axis of the shaft 10, and each pin, at its outer end, is provided with a circular flange by means of which the pin is bolted or otherwise suitably fixed to the underlying block 32. The main body of each pin 34 is round in cross section and extends radially of the axis of the shaft 10 in alignment with the other pin associated with the same sleeve 24, 26. Each pin 34 extends through the block 32 mounting the same and through the sleeve 24, 26 and then through an elongated slot 36 extending longitudinally of and through the wall of the shaft 10, there being one such slot associated with each pin. Each pin 34 is engaged at its inner end within a recess in one of the lead nuts 20, 22 which serves to fix the lead nut against rotation about the axis of the shaft 10. Accordingly, as the lead screw 12 is rotated in either of both directions of movement thereof, the sleeves 22, 24 will be 7 simultaneously moved longitudinally of the shaft 10, and in the specific embodiment will be moved in opposite directions. With particular reference to FIGS. 2 and 3, disposed concentrically of and spaced radially outwardly of the shaft 10 is a first series of segments 40 disposed equiangularly about the axis of the shaft 10. In the specific embodiment there are three such segments, and each comprises a base 42 on which is mounted a pair of shell members 44, 46. Each of the shell members is particylindrical in shape with the outer surface thereof disposed concentrically of the axis of the shaft 10. Each of the shell members is releasably mounted on its base 42 by means of a bolt 48 extending outwardly of the drum axis through an elongated slot 50 in the base and threadedly engaged in a recess in the shell member. The slot 50 extends parallel to the axis of the shaft 10, whereby upon loosening of the bolt 48, the respective shell member may be adjusted longitudinally of the shaft axis within the limits of the length of the slot 50. Each shell member is provided with additional threaded recesses 52 selectively engageable by the bolt 48 to permit further adjustment of the shell member parallel to the shaft axis to provide for different overall drum lengths. A spacer 54 is disposed between the next adjacent ends of each associated pair of shell members 44, 46 and is releaseably mounted on the base 42. The spacer is removable and may be replaced by a spacer of different width, as measured axially of the drum, so as to fill the space between the next adjacent ends of the shell members when the same are adjusted farther apart to increase the overall drum length.

A second series of segments 56 are disposed about the shaft axis in radially spaced relation thereto and are interposed respectively between the segments 40 of the first series thereof; in other words, the segments 40 and 56 are arranged alternately about the shaft axis. Each segment 56 comprises a base 58 similar to the base 42 and a pair of shell members 60, 62 similar to the shell members 44, 46 previously described. A spacer 64, similar to the spacer 54, is provided for each segment 56. The shell members 60, 62, as well as the spacer 64, are mounted on the base 58 in the same manner as described in connection with the shell members 44, 46 and spacer 54. In the specific embodiment shown, the shell members 60, 62 are somewhat wider, as measured circumferentially of the drum, than the shell members 44, 46. As shown in H6. 2 the edge portions of each of the shell members 60, 62 which extend parallel to the axis of the shaft 10 are beveled so as to lie in a plane extending generally in a chordwise direction relative to the external surface of the shell member. The beveled edge portions of the shells 60, 62 are in overlapping engagement with mating surfaces extending along the corresponding edge portions of the shell members 44, 46 when the segments are in drum expanded condition as viewed in FIG. 2, at which time the external surfaces of the segments 40 and 56 collectively define a cylindrical building surface disposed concentrically of the axis of the shaft 10.

Disposed between the sleeve members 24 and 26 is a central hub 66 comprising a generally cylindrical, tubular center portion 68 disposed coaxially over the shaft 10 and fixed relative thereto by suitable means, as at 70. The hub 66 terminates at its opposite ends in a pair of radially outwardly extending circular flanges 69, 71 which in turn terminate at their radially outer ends in generally annular block portions 72, 74 which are spaced radially outwardly from the shaft 10. Each of the segments 40, 56 have a pair of pistons 76, 78 depending from the base 42, 58 thereof. Each such pair of pistons is suitably fixed to its associated base member and extends radially of the axis of the shaft 10. The pistons of each pair thereof are aligned in a plane containing the shaft axis, and are spaced apart axially of the drum with the pistons of each pair received respectively in cylinders in the block portions 72, 74 of the hub 66, the cylinders extending through the block portions 72, 74 in a direction radially of the shaft axis.

In order to effect movement of the segments radially of the drum axis, each of the segments is pivotally connected to one end of a pair of links the other end of which are pivotally connected to the sleeve members 24, 26. More particularly each piston 76 associated with a segment 40 is in the form of a cylindrical bar and has a slot 80 extending longitudinally therethrough and radially partially therethrough. Each of the cylinders receiving the pistons 76 has a similar slot in the wall thereof extending the full length of the cylinder and registering with the slot 80 with the piston. Received within each slot 80 in each piston 76 is a link 82. The outer end of each link 82 is pivotally mounted on the associated piston 76 for movement about an axis extending at right angles to and radially spaced from the axis of the shaft 10. The other or inner end of each link 82 is pivotally connected to a projection 84 on an associated one of the block members 32 for movement about an axis extending parallel to the pivotal axis of the outer end of the link. The block portions 72, 74 of the hub 66 are spaced radially outwardly of the shaft a distance sufficient to provide clearance for the projections 84 to be disposed between the block portions and the shaft 10 when the drum is in expanded condition, as shown in FIG. 1. As will also be seen from FIG. 1, when the drum is in its expanded condition, the links 82 are on center; or in other words, the pivotal axes of each link lie in a common plane extending at right angles to the axis of the shaft 10. Each of the links 82 is generally rectangular in cross section and has a thickness less than the width of the slots 80 and 83 in the pistons 76 and block portions 72, 74, for a purpose which will be hereinafter apparent.

Movement of the segments 56 radially of the drum axis is effected in a manner similar to movement of the segments 40. More particularly, a pair of links 86 are associated with each segment 56 and are pivotally connected at their outer ends to the segments for movement about axes extending at right angles to an spaced radially from the axis of the shaft 10. The inner ends of the links 86 are pivotally mounted on projections 88 extending from associated ones of the blocks 32 interposed between the blocks 32 associated with the links 82 and segments 40. The pivotal axis of the inner end of the links 86 is parallel to the pivotal axis at the outer end of these links. The pistons 78 are of a construction similar to the pistons 76 and are provided with slots 90 similar to and for the same purpose as the slots 80 and the pistons 76. Further, the block portions 72 and 74 are provided with slots 92 in association with the cylinders therein receiving the pistons 78 with the slots 92 being similar in structure and function to the slots 83 previously described. The slots 90 and 92 have a width which is greater than the thickness of the links 86 to permit the links to be disposed within the slots in the pistons. In the specific embodiment shown, the outer ends of the links 86 are pivotally mounted to the pistons 78 which are in turn fixed relative to the bases 58 of the segments 56.

In the operation of the drum described above, the drum will be in its expanded condition as shown in FIGS. 1 and 2 during the building of a tire thereon. After the tire has been built, the drum is collapsed for the removal of the tire therefrom. The collapse of the drum is accomplished by rotating the lead screw 12 in a direction to cause simultaneous movement of the sleeves 24, 26 longitudinally of the axis of the drum. In the specific embodiment shown in the drawing, rotation of the shaft 10 is accomplished by insertion of a suitable tool in one of a plurality of holes 100 in a disc 102 fixed relative to one end of the shaft 10. The holes 100 are arranged in a circle concentric with the shaft axis. One end of the screw 12 is provided with a tool engageable portion 104 by means of which the screw may be rotated while the shaft is held stationary by a suitable tool engaged in one or more of the holes 100.

In the specific embodiment shown, the sleeves will simultaneously move in opposite directions axially of the drum, and more particularly will move in opposite directions and axially outwardly of the drum. This movement of the sleeves will draw the inner ends of the links 82 axially outwardly of the drum with attendant radial movement of the pistons 76 and their associated segments 40. In the case of the segments 56, the initial axial outward movement of the inner ends of the links 86 will cause the segments 56 to move radially outwardly a small amount and then move radially inwardly of the drum axis. This action of the segments 56 is due to the fact that the pivot axes at the inner ends of the links 86 are spaced axially inwardly of the drum relative to the pivot axes at the outer end of the links when the drum is in its expanded condition, shown in FIGS. 1 and 2. Accordingly, during initial movement of the inner ends of the links in an axially outward direction and until the links pass through their oncenter condition, the segments 56 will move upwardly whereupon continued outward movement of the inner ends of the links 86 will cause the segments 56 to move radially inwardly. The radial inward movement of the links 56 thus lags the corresponding movement of the segments 40 so that in the collapsed condition of the drum the segments 56 will be disposed radially outwardly of the segments 40, as shown in FIG. 3. Also this final disposition of the segments is accentuated by the fact that the pivot axes of the links 82 are spaced apart farther than are the axes of each link 86.

In order to return the drum from its collapsed condition to its expanded condition of FIG. 2, the lead screw 12 is rotated in the opposite direction effecting simultaneous axially inward movement of the sleeves 24 with corresponding movement of the inner ends of the links 82 and 86. As the sleeves 24, 26 move inwardly toward each other the links 82 return from the dotted line position shown in FIG. 1 to the solid line oncenter position. The links 86 also move from the dotted line position shown in FIG. 1 toward and through an oncenter position and beyond to the solid line position shown in FIG. 1. In other words, the links 86 move through center in a togglelike manner whereby the segments 56 are moved to a radius slightly greater than that shown in FIGS. 1 and 2 and are then moved inwardly into overlapping engagement with the segments 40. Axially inward movement of the sleeves 24, 26 is limited by engagement of the projections 88 of the blocks 32 associated with the links 86 with the flanges 68 and 70 on the center hub 66.

While certain representative embodiments and details have been shown for the purpose of illustrating the invention, it will be apparent to those skilled in this art that various changes and modifications may be made therein without departing from the spirit or scope of the invention.

What is claimed is:

l. A collapsible tire-building drum comprising an elongated rotatable shaft; a first series of segments disposed in angularly spaced relation about the shaft and each having an arcuate external surface disposed concentrically of the shaft axis of rotation; a second series of segments disposed about said axis, the segments of said second series being interposed respectively between the segments of said first series and each having an arcuate external surface disposed concentrically of the shaft axis and forming with said external surfaces of the segments of said first series a continuous cylindrical building surface disposed concentrically of said axis; and means for effecting movement of said segments radially of said axis including a pair of links associated with each of said segments, one end of each link being pivotally connected to its respectively associated segment, a pair of members each movable longitudinally of said axis between first and second positions, the other ends of the links of each said pair thereof being pivotally connected respectively to said pair of members, the links associated with said first series of segments passing through center during movement of said members between their first and second positions, the links associated with said second series of segments being oncenter in the first position of said members, and means for simultaneously moving said members longitudinally of said axis.

2. A tire-building drum as claimed in claim 1, in which the pivotal axes of each link associated with said second series of segments are spaced apart a distance greater than the pivotal axes of said links associated with said first series of segments.

3. A tire-building drum as claimed in claim 1, wherein each segment includes a base and a pair of shell members disposed radially outwardly of the base with the shell members being disposed on opposite sides of the circumferential centerline of the drums, means for releaseably connecting each pair of shell members to its base and for varying the position of said shell members longitudinally of said axis, a replaceable spacer disposed between each pair of shell members, and releasable means mounting each spacer to its respective base.

4. A tire-building drum as claimed in claim 1, in which each segment of said first series thereof has a pair of edge portions extending parallel to said axis and overlapping the next edge portions of the segments of said second series thereof when said members are in said first position thereof.

5. A tirebuilding drum as claimed in claim 1, further comprising a central hub fixed relative to said shaft, said hub having a pair of cylinders respectively associated with each segment, a pair of pistons respectively received in each pair of cylinders, each pair of pistons being fixed for movement with one of said segments.

6. A tire building drum as claimed in claim 5, in which said cylinders extend radially of said axis and each respectively associated pair of cylinders are aligned in a plane containing said axis, said hub being provided with a slot associated with each said cylinder, each slot extending parallel to the longitudinal axis of the cylinder and opening into the cylinder, each piston having a slot aligned with the slot in the cylinder in which it is received, one of said links being disposed within the slot in each of said pistons and being aligned with the slots in the piston and associated cylinder, said slots lying in planes extending at right angles to the pivotal axes of said links and being of a width greater than the thickness of said links.

7. A tire-building drum as claimed in claim 6, in which said one end of each link is pivotally mounted on its respectively associated piston.

8. A tire building drum as claimed in claim 6, wherein said cylinders are in a pair of portions of the hub which are spaced radially outwardly of said shaft, each said member including a plurality of portions projecting between one of said portions of the hub and the shaft, the other end of the links being pivotally mounted respectively on said projecting portions.

9. A tire-building drum as claimed in claim 8, in which the pivotal axes of each link associated with said second series of segments are spaced apart a distance greater than the pivotal axes of said links associated with said first series of segments.

10. A tire-building drum comprising an elongated shaft, a hub coaxially disposed about the shaft and fixed relative thereto, a plurality of segments disposed about the shaft radially outwardly of said hub, said hub being provided with a pair of cylinders respectively associated with each segment, the pairs of cylinders being spaced apart angularly about the shaft axis with the cylinders of each pair being aligned in a plane containing the shaft axis and extending radially of said axis, a piston received in each said cylinder and fixed at one end relative to the respectively associated segment, said hub being provided with a plurality of slots respectively associated with said cylinders, said slots extending parallel to the axis of the cylinders and respectively opening thereinto, each piston having a slot extending parallel to and communicating with the slot in the respective cylinder, a link extending longitudinally of and received within each piston in alignment with the slots in the piston and cylinder, each link having a thickness less than the width of the slots in the respective piston and cylinder, one end of each link being pivotally connected to the respectively associated segment, and means for simultaneously moving the other ends of said links longitudinally of the shaft axis.

11. A tire building drum as claimed in claim 10, in which said one end of each of said links is pivotally mounted on the respectively associated piston.

12. A tire-building drum as claimed in claim 11, in which said means for moving the other ends of said links comprises a pair of members movable longitudinally thereof, the other end of one link of each pair being associated with one of said members, the other end of the other link of each pair being associated with the other of said members, said cylinders being contained within a pair of portions of said hub which are spaced radially outwardly of said shaft, each of said members having a plurality of projections extending between said portions of the hub and said shaft, the other ends of said links being pivotally mounted on said prpjections. 

1. A collapsible tire-building drum comprising an elongated rotatable shaft; a first series of segments disposed in angularly spaced relation about the shaft and each having an arcuate external surface disposed concentrically of the shaft axis of rotation; a second series of segments disposed about said axis, the segments of said second series being interposed respectively between the segments of said first series and each having an arcuate external surface disposed concentrically of the shaft axis and forming with said external surfaces of the segments of said first series a continuous cylindrical building surface disposed concentrically of said axis; and means for effecting movement of said segments radially of said axis including a pair of links associated with each of said segments, one end of each link being pivotally connected to its respectively associated segment, a pair of members each movable longitudinally of said axis between first and second positions, the other ends of the links of each said pair thereof being pivotally connected respectively to said pair of members, the links associated with said first series of segments passing through center during movement of said members between their first and second positions, the links associated with said second series of segments being oncenter in the first position of said members, and means for simultaneously moving said members longitudinally of said axis.
 2. A tire-building drum as claimed in claim 1, in which the pivotal axes of each link associated with said second series of segments are spaced apart a distance greater than the pivotal axes of said links associated with said first series of segments.
 3. A tire-building drum as claimed in claim 1, wherein each segment includes a base and a pair of shell members disposed radially outwardly of the base with the shell members being disposed on opposite sides of the circumferential centerline of the drums, means for releaseably connecting each pair of shell members to its base and for varying the position of said shell members longitudinally of said axis, a replaceable spacer disposed between each pair of shell members, and releasable means mounting each spacer to its respective base.
 4. A tire-building drum as claimed in claim 1, in which each segment of said first series thereof has a pair of edge portions extending parallel to said axis and overlapping the next edge portions of the segments of said second series thereof when said members are in said first position thereof.
 5. A tire building drum as claimed in claim 1, further comprising a central hub fixed relative to said shaft, said hub having a pair of cylinders respectively associated with each segment, a pair of pistons respectively received in each pair of cylinders, each pair of pistons being fixed for movement with one of said segments.
 6. A tire building drum as claimed in claim 5, in which said cylinders extend radially of said axis and each respectively associated pair of cylinders are aligned in a plane containing said axis, said hub being provided with a slot associated with each said cylinder, each slot extending parallel to the longitudinal axis of the cylinder and opening into the cylinder, each piston having a slot aligned with the slot in the cylinder in which it is received, one of said links being disposed within the slot in each of saId pistons and being aligned with the slots in the piston and associated cylinder, said slots lying in planes extending at right angles to the pivotal axes of said links and being of a width greater than the thickness of said links.
 7. A tire-building drum as claimed in claim 6, in which said one end of each link is pivotally mounted on its respectively associated piston.
 8. A tire building drum as claimed in claim 6, wherein said cylinders are in a pair of portions of the hub which are spaced radially outwardly of said shaft, each said member including a plurality of portions projecting between one of said portions of the hub and the shaft, the other end of the links being pivotally mounted respectively on said projecting portions.
 9. A tire-building drum as claimed in claim 8, in which the pivotal axes of each link associated with said second series of segments are spaced apart a distance greater than the pivotal axes of said links associated with said first series of segments.
 10. A tire-building drum comprising an elongated shaft, a hub coaxially disposed about the shaft and fixed relative thereto, a plurality of segments disposed about the shaft radially outwardly of said hub, said hub being provided with a pair of cylinders respectively associated with each segment, the pairs of cylinders being spaced apart angularly about the shaft axis with the cylinders of each pair being aligned in a plane containing the shaft axis and extending radially of said axis, a piston received in each said cylinder and fixed at one end relative to the respectively associated segment, said hub being provided with a plurality of slots respectively associated with said cylinders, said slots extending parallel to the axis of the cylinders and respectively opening thereinto, each piston having a slot extending parallel to and communicating with the slot in the respective cylinder, a link extending longitudinally of and received within each piston in alignment with the slots in the piston and cylinder, each link having a thickness less than the width of the slots in the respective piston and cylinder, one end of each link being pivotally connected to the respectively associated segment, and means for simultaneously moving the other ends of said links longitudinally of the shaft axis.
 11. A tire building drum as claimed in claim 10, in which said one end of each of said links is pivotally mounted on the respectively associated piston.
 12. A tire-building drum as claimed in claim 11, in which said means for moving the other ends of said links comprises a pair of members movable longitudinally thereof, the other end of one link of each pair being associated with one of said members, the other end of the other link of each pair being associated with the other of said members, said cylinders being contained within a pair of portions of said hub which are spaced radially outwardly of said shaft, each of said members having a plurality of projections extending between said portions of the hub and said shaft, the other ends of said links being pivotally mounted on said projections. 